Thorn Cycles Forum
Community => Non-Thorn Related => Topic started by: Danneaux on August 15, 2013, 09:14:12 pm
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Hi All!
I'm considering a suspension seatpost for my Nomad Mk2 when I use it on logging roads without a load. Usually, I just post (stand up briefly) when hitting a bump with my unladen bikes on such terrain, but that is less-often possible when tootling along in low gears uphill with a full-on touring load. Despite what I initially thought, the front of the bike is not problem; I just bend my elbows and do fine with that. It is the compressive loads coming up my spine that have a whiplash effect on my neck and I can really feel that after several hours. Unlike when road riding, the size of the bumps makes tire cross-section and lower pressures less effective in absorbing the larger hits while seated. For road use or extended touring, I'd still choose a lower-maintenance rigid post, but a sus-post would really help when I'm riding the bumpy stuff in the hills and mountains that surround my town.
I have experience with two suspension seatposts on my tandem. The stoker gets a USE telescopic seatpost I heavily machined and modified to reduce stiction and uses a combinaton of elastomers and a repurposed automobile valve spring. It works well, but would not be to my taste for the Nomad because there is the slightest bit of rotation that can be felt while pedaling and I find that annoying. My stokers have all been very enthusiastic about it, and say it performs well even on the "bigger hits" experienced by stokers when going on rougher surfaces (the stoker sits nearer the rear wheel and so feel the bumps more than I do as Captain, suspended midway between a long wheelbase).
I have a different sort of sus-post at the Captain's saddle. It uses an elastomer in compression that works a bit like a broomstick in a door hinge. It is just the ticket for absorbing the little bit of "road buzz" that comes up through the long wheelbase to the captain's saddle. Its one drawback is it tips the saddle rearward on compression, so I have to set the saddle up with a bit more forward tilt than usual to compensate. Not a problem with the leather-covered Avocet Touring II saddle I use there.
I think I'd prefer a parallelogram seatpost on the Nomad for several reasons. For one, under compression, the saddle moves downward and rearward, making for a bit less vertical compression and so affects saddletop-to-BB distance a bit less. Second, the geometry seems likely to be a bit more responsive than a telescoping post, which is about halfway locked-out when examined in light of the compressive forces coming up through the rear wheel.
There's three leading candidates so far in my search, and all are available in 27.2mm to fit my Nomad's seatpost shim. Thudbuster has a long-travel parallelogram post with two tunable diagonally-placed elastomers. Thudbuster also offer a shorter-travel post whose parallelogram is filled with a single, shaped elastomer that comes in several durometers. These are both nice, have received stellar reviews for their respective intended usage, and are expensive.
Alternatively, SR-SunTour offer a parallelogram seatpost that has been freshly redesigned for 2012, the SP 12-NCX: http://www.flickr.com/photos/29976052@N08/8022574000/sizes/o/in/photostream/
...and...
http://www.srsuntour-cycling.com/index.php?screen=sh.detail&tnid=3731
The price is considerably less than Thudbusters', and the reviews have been uniformly good on this new model at German and Dutch online vendors and among the pedelec crowd, even in comparison to Thudbuster. Our own Stuntpilot has one on his Raven Torla, and was initially impressed by it and is gathering long-term data on its performance. In an earlier post, he mentioned setting his tension so his post was effectively a rigid until he hit a large bump. That appeals to me. At that time, the post made a clicking noise when it hit the rebound stop, but was infrequent enough to be no bother. The SunTour uses brass bushings and rebuild kits are readily available to keep them fresh.
One thing that concerns me about the SunTour post is the apparent lack of rebound control. It uses a very clever design where a roller vertically compresses a spring-loaded shaft. This makes for a low-friction, very responsive post, but I'm concerned its action might not be well-controlled. Here's a video showing it in action at a bike show: http://www.youtube.com/watch?v=hN8v_SEWPto
Wondering if any of you have experience with suspension seatposts, if you also prefer a parallelogram design over telescopic, and what you thoughts are on the SunTour versus Thudbuster(s) or perhaps some other model or design.
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EDIT: I just came across another possibility by German component supplier XLC: http://www.xlc-parts.de/produkte_detail_de,854,33700,detail.html
Google-translated to English here: http://translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.xlc-parts.de%2Fprodukte_detail_de%2C854%2C33700%2Cdetail.html&act=url
It uses an elastomer with adjustable preload to produce only 25mm of travel inits parallelogram linkage.
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I should note I'd like a seatpost with considerable layback/setback to get a good position on the bike while clamping the saddle rails midway to reduce breakage. I currently use a Thorn/Zoom long-layback 'post and it works fine. Thanks in advance for sharing your thoughts.
Best,
Dan. (...who <Ungh!> could use something to help with the <Ungh!> larger bumps while touring on <Ungh!> really rough roads)
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Maybe try a Brooks Flyer saddle instead? Similar top to B17, but with fairly stiff springs.
I generally prefer B17 for my bikes, but have a B66 Champion (the twin-rail predecessor to the Flyer) on my old 5-speed. On off-road riding I find this smooths out the worst of the bumps without noticeably compromising on-road pedalling efficiency.
Had the B66 Champion since 1984, done over 60,000 kms with it, the leather is a bit cracked now but the saddle is still very comfortable.
Downsides of a sprung saddle - extra weight, and may make creaky sounds. But probably simpler than a suspension seatpost, and doesn't develop sloppiness with wear over time.
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Maybe try a Brooks Flyer saddle instead? Similar top to B17, but with fairly stiff springs.
Thanks for the thoughtful suggestion, Martin! I really wish this would work as a solution for me, as it is simpler and more direct, just as you say.
I tried a Flyer some years ago, and sadly ended up selling it to my neighbor. I found the springs were just too stiff to provide much (any) suspension effect for me even on larger bumps with my back at a 45° angle.
Similar experiences here: http://www.bikeforums.net/showthread.php/227872-Brooks-saddle-springs-%96-is-ride-softer-with-use
I really liked the idea, and wished very much I could have substituted slightly softer springs to make it work on muting the Big Bumps without bouncing much on the smaller ones. The B.17 is the perfect match in width and shape for my needs, and the Flyer felt the same. I really wouldn't want to go wider or narrower in the Brooks line, or to a different shape when this works so well for me.
Downsides of a sprung saddle - extra weight, and may make creaky sounds. But probably simpler than a suspension seatpost, and doesn't develop sloppiness with wear over time.
All very true. I'd sure be willing to give a Flyer another try if I could just source the slightly softer springs I would need -- and then get then installed.
Best,
Dan. (...who may give this some more considered thought, as it is a Preferred Solution™)
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I think a lot depends on your saddle. I didn't get on well with combining my B17 with a suspension post. I think it slowed down the break-in process. Also, for me getting the height of the saddle just right is critical for a Brooks and also for my knees. We are talking mm here! With a suspension post the height and geometry becomes variable. i suppose a sprung flyer or B67 would have some of the same issues but not tried them.
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According to this reviewer, the springs in recent saddles are stiffer than those in my old saddle:
http://swhs.home.xs4all.nl/fiets/tests/zadels/index_en.html#Brooks_b66_champion
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...for me getting the height of the saddle just right is critical for a Brooks and also for my knees. We are talking mm here!
Hi Geo'!
I think you've touched on the "stopper" that has been lying in the back of my mind wrt suspension seatposts.
After injuring my knees in that car wreck at age 16, I've had to be really careful not to re-aggravate them, and -- just as you said -- even mm of difference in saddle height start the bone-deep aching again. My recent adventure trying clipless shoes knocked me right off the bike, made even walking difficult, and I've lost a lot of sleep due to the knee pain resuming. I never figured the lightest pedal spring-release tension and heel-out movement could possibly aggravate such ancient injuries. I seem to have found my solution in multirelease cleats and "baby-mode" Shimano T400 pedals dialed back to minimum tension.
I'm not sure I would fare as well wrt to dynamic changes in saddle height -- at least not while I'm still icing my knees. Best to wait and let things settle down, then re-evaluate the sus-post thing.
It may well be the "best" sus-post solution for me is one that can be tuned to act as a rigid post in all circumstances except when encountering the Big Bumps -- as Richard (Stuntpilot) has set his. Adjusted that way, the saddle would "give" only momentarily when really needed and my knees wouldn't have to deal with much change in height.
Martin, I have to agree...Brooks' springs have become thicker and less responsive in recent years.
Thanks, fellows; really helpful input.
Best,
Dan.
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I thought yesterday of suggesting a Brooks extra-spring saddle ("extra" because the leather hammock is already a spring) but refrained because the ones with the right springs, with progressive suspension, are the helical coil-sprung models, and the best ones among them are wider than the B17 — and Dan had earlier in another thread ruled out saddles wider than the B17.
I like the B73, which I bought on a halfprice sale at SJS as a wild experiment and loved so much that I have ridden nothing else since, even giving up my beloved Cheeko90 (a seat rather than a saddle) for the Brooks. The street myth from people who haven't ridden the triple-coil sprung Brooks that it sways from side to side is rubbish; it doesn't because the springs are too stiff. But they are tempered just right to keep the road buzz out of your coccyx and thence your spine, so the ride is very relaxing. On washboard and brandnew cheap chipseal surfaces they're too stiff to help much (I use the B73 in a complete system with 60mm low pressure balloons), or perhaps one just notices more because the rest of the ride is so plush. But they shine in crashing through potholes, which here is inevitable, the more so if you ride fast on my narrow roads and lanes, when you often have to ride through the pothole as the alternative might be an incident with a car or a spill. At my age I can't afford a broken hipbone, so a saddle that helps keep you on the road regardless of potholes is worth twice the full price of the Brooks.
Unfortunately the B73 is the third heaviest of the current Brooks saddles (the B135 and B190 are heavier than the B73 by more than the weight of the B72!). But there's a lighter version called the B72, very rare but listed by SJS. It doesn't have the full helical springs of the big brother B73 (now revealed as a brilliant compromise!), but what makes the coiled springs so good isn't their coiling but their length; coiling is not an operating function but a space-saving device. This B72 has a pair of extra-long sprung rails with a single longitudinal coil in each. See the frame at http://www.sjscycles.co.uk/page/find/?name=Brooks%20B72&page=1 The B72 should thus be lighter -- compare with the B73 components and assume heavier leather too at http://www.sjscycles.co.uk/page/find/?name=Brooks%20B73&page=1 -- than the B73 by a good deal (1100 - 690 = 410gr), and almost as stiff/compliant under the relevant conditions as the B73, because of the very long effective rail. Also, probably important to a dyed in the wool traditionalist like Dan, the B72 looks more like a proper fast touring cycle saddle than the B73, which is clearly designed for the middle-aged sybarite's sitzplatz.
I wouldn't use any of the Brooks saddles, including the B17, with a sprung seat post. The B17 is itself already a double suspension medium of leather and slightly flexible rails. Brooks lucked out with the combination because the leather is so extremely adaptable. But adding a third suspension medium with yet another set of frequencies is a recipe for introducing disastrously tiring microfrequencies into your bum and thence into your spine and nervous system even on good roads, while doing nothing to make bad roads more tolerable.
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Dan, I've had the USE in two or three of the cheaper models (no better in use than really cheap stuff with a one-year lifespan, though more tuneable), a Suntour NCX and the smaller Thudbuster because it was all that would fit on that bike. The Suntour works just as well at half the price of the Thudbuster and better than the more expensive USE. Both the parallelograms are superior to the USE in use. I can't tell you anything about longevity because I kept none but the USE very long and that only for a year. In my opinion, suspension seat posts aren't a solution or in many cases even an amelioration but the cause of further complications and problems.
Andre Jute
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I have just posted a review of the SR Suntour SP12-NCX on my blog. Detailing my experience of the seat post, it adds comments on the good and bad with plenty photos.
Despite the down sides, I love the SR Suntour post and how it performs on a long tour ...
http://www.touronabike.com/sr-suntour-sp12-ncx-suspension-seat-post-review/
Hope that provides some input for those deciding to buy or not.
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Wow! Richard! Is that ever helpful; thanks so much for this.
All the best,
Dan. (...who will re-read as he ponders further)
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http://www.touronabike.com/sr-suntour-sp12-ncx-suspension-seat-post-review/
Thank you so much for that. Makes me want to try it again -- the last time I had one, briefly, was before the recent redesign with brash bushings etc, though I hasten to add I didn't sell it on for any quality issues but simply because it wasn't in use after I changed bikes and saddles and someone else lusted after it. But now Julian has sent me his adaptor for Brooks twin rail to micro-adjustable seat post, so I could conceivably fit any seat post. Mmm...
That's a really good point in the article about a one-motion return to the original position, and the effect on control of the bike over rough roads or in unexpected situations.
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Specialized have recently released a carbon suspension post called the COBL G0BL-R> You can read info on it here: http://www.cxmagazine.com/specialized-cobl-goblr-ergon-cr3-suspension-seatposts-cyclocross-road
I find it interesting as it has no moving parts, its basically a leaf spring.
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;) how nice to share .... remain interesting for all of us on 27,2 and .. for the familly !
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Specialized have recently released a carbon suspension post called the COBL G0BL-R> You can read info on it here: http://www.cxmagazine.com/specialized-cobl-goblr-ergon-cr3-suspension-seatposts-cyclocross-road
I find it interesting as it has no moving parts, its basically a leaf spring.
YES its very cool and works well.
Pete
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Dear Dan,
I use a Cane Creek Thudbuster LT when the Catalyst is carrying me over MTB trails with a Rock Shox Reba RLT 100mm fork up front. It works well to smooth out the small, high frequency bumps that can sap energy and pummel the derrier over a day's riding (no innuendo free way of expressing this, let's not let things slide into a mire of innapropriate smuttiness, eh?). It affords somewhat greater traction over such sections when taken, at speed. This effect seems to be enhanced by the rearward actuation of the suspension which throws ones weight over the rear wheel. The compression is responsive, smooth and progressive. The movement keeps the seat - pedal distance constant which contributes to the natural feel of the system.
Drops greater than 6" or so and technical sections still need to be negotiated standing up on the pedals. The post does not give the big hit, freeride capability you may be looking for on the fully loaded Nomad dragging the extrawheel.
The first post I brought was replaced under warranty by CRC when one of the bolts securing the halves of one of the parallelogram arms sheared. I am just within the upper weight limit for the system (100kg of solid lard vs 105kg) but was disappointed that it failed so soon after moderate riding. The new post has lasted the past five years with no trouble.
Being so hefty I had to order the appropriatly firm purple elastomers seperately which cost a further £10 or so. The included elastomers allow tuning of the suspension to accomodate riders between about 60 - 90 kg in 5kg increments.
The neoprene cover is necessary to protect the bearings which are simple bronze bushings with open ends. Mine has developed abrasion holes so I'll need to think of a repair approach. £20 for a replacement is an affront even to my fairly primitive economic understanding.
Overall it was £90 well spent when I got it six years ago. I notice that they are double that now.
Yours, James
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Hi James!
Your post is really timely as I have turned my focus increasingly toward the Thudbuster LT.
I have been looking for the sort of performance you describe -- the smoothing of high-frequency bumps -- figuring I would still have to post (stand) over more rugged stuff. I see Andy Blance continues to offer the Thudbuster LT as an option in the Nomad brochure, though he says he and Fiona use it on their MTBs and not their touring bikes.
On the one hand, I dislike the idea of adding extra weight (unlikely to be noticed in the 20kg weight of the bike and the weight difference between the LT and original post isn't much) and complexity (one more thing to wear and potentially break), but it would be really nice to have something to "take the edge off" when touring largely unladen on rough logging roads, fire trails, and such where many miles of large-ballast rock (see attached pic) must be traversed before hitting the really rough-stuff. It is the ballast that is proving a bit problematic on the unladen bicycle. It reminds me of Belgium's cobbles -- nothing in the way of a really hard hit, but just lots and lots of constant vibration. Putting a touring load on the bike of course smooths things out considerably, the Nomad really coming into its own with an expedition load (exactly what I need for full-on backcountry touring). My preferred option was a Brooks Flyer, but I found the springs almost completely unresponsive for my riding position and sold it on in disappointment. If only the springs had been softer and more responsive for my use! This is what caused me to turn toward sus-posts. A telescopic model works fine for my tandem stokers, but I want to avoid changes in leg-length, so parallelogram models hold greater appeal for me.
I'm a little unnerved by your breakage, but hope my 78kg and 45° back angle won't press the bolts unduly in service. Makes me think it would be Very Wise to carry a spare bushing and bolt with me on longer tours if I go this route. I'm guessing the forward lean of drop 'bars will help a bit as well. Bike4Travel partner Chantal Kwakkelstein in Rotterdam published an encouraging review of her experience in Dutch here: http://www.bike4travel.nl/article_info.php?articles_id=25 summarized in translation:...I am now on two bikes, but the Thudbuster is simply moved along. The suspension is perfect! So subtle that you do not feel it, but the bumps on the paths not. And after long days on unpaved trails, no problems with my back! Now after 25,000 miles he still works perfectly and no play!
I'm hoping the parallelogram linkage will indeed work to keep saddle-to-BB distance fairly constant, at least compared to telescopic posts. Jimmer, do you find the downward-and-rearward movement has you really reaching for the handlebars, or is it pretty tolerable and largely unnoticeable? I read about the LT having as much as 76mm/3in of travel and wonder how much of that is rearward. I'm guessing about half the total travel? Any interference between Brooks saddle rails and linkage as Richard found initially on his SR-SunTour?
I'm still unsure whether the LT is the route to go or the ST...or something with similarly short travel like Richard's SR-SunTour ( http://www.srsuntour-cycling.com/index.php?screen=sh.detail&tnid=3731 ) or the Tamer PivotPlus XC (http://www.amazon.com/Tamer-Pivot-Plus-Suspension-Seatpost/dp/B00A214PR6 ).
Stateside, I can get the current Thudbuster LT for as little as USD$139, equivalent to £86, so the price isn't as bad as I'd feared. I would definitely want the neoprene cover. I wonder if ShoeGoo or McNett SeamGrip would make a good patch for the holes?
Thanks again for your thoughts, James. Anyone else out there running a sus-post?
All the best,
Dan. (...who would like to travel in a less ehm, shocking manner)
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Those Photos are stunning Dan and they also tell a tale,you should not be cycling on roads (if you could call it a road )like that so might be better of with an extra pair of walking boots.
think about it how often would you be on that kind of terrane not long i suspect. your arse will thank you for walking. ;)
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...how often would you be on that kind of terrane...
Hi Jags! Except for overseas tours, I always start from and return to my own front door, so there's a fair number of paved-road miles before I get to the rough stuff. Once there however, I ride it for 12-17 hours/day. This ballast is the relatively good stuff, improved for the logging trucks and machinery with the large, loose rock providing good drainage for rains to prevent slides. Soon after that, things take a turn for the unimproved with big rocks, roots, and potholes and such.
That ballast rock is large and it is sharp and it tends to roll a bit under my tires, so I can't always stand on the pedals as I'd like (see sample pic below). That is what has me thinking "sus-post" at present.
A lot of the roads have been carved out of the mountainsides by Cat tractor (usually D8s whose elevated drive cogs reduce track wear), and aren't made to common road standards. Things get really steep on the access roads to potential timber sales that will eventually be logged. I can usually climb up grades as much as 21% with the Rohloff's 15in low, but anything beyond that I push. I can go down steeper grades, but I have to use my 'bar tops and interrupter levers to keep my weight well back to prevent endos (see more pics below; my new camera has a level-shot indicator so I can accurately gauge slopes). On steep downhills I have to sit down rather than post, and that's where a sus-post would help comfort over the course of a long day atop the saddle on really rough roads. Contorting myself into a long, low, and rearward posture kinks my neck upward for the duration of a rough downhill and I can feel it afterwards....you should not be cycling on roads (if you could call it a road )like that so might be better of with an extra pair of walking boots.
Aw, jags! What fun would that be? ;D
All the best,
Dan. (...who wouldn't mind a little spring in his ride)
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Ha Dan boy your good friend Anto would be walking up those hills that i can surly guarantee ;D ;D
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Did you get the Cane Creek Thudbuster LT in the end? How is it in combination with a Brooks saddle?
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Yes CT, the Thudbuster LT works beautifully with my Brooks B.17 on the Nomad Mk2. So did the ST, but did not have enough travel for my needs on really rough roads.
I may fit an ST under the B.17 Champion Special saddle on my other rando bike. The ride has always been harsh at the rear, the Champion Special saddle is made of extra-thick leather, and the ST will still fit nicely in the limited clearance available on this bicycle, which has a horizontal top tube.
Others may have differing experiences, but I've found both flavors of Thudbuster to be nicely compatible with my Brooks B.17s.
Best,
Dan.
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Yes CT, the Thudbuster LT works beautifully with my Brooks B.17 on the Nomad Mk2. So did the ST, but did not have enough travel for my needs on really rough roads.
I may fit an ST under the B.17 Champion Special saddle on my other rando bike. The ride has always been harsh at the rear, the Champion Special saddle is made of extra-thick leather, and the ST will still fit nicely in the limited clearance available on this bicycle, which has a horizontal top tube.
Others may have differing experiences, but I've found both flavors of Thudbuster to be nicely compatible with my Brooks B.17s.
Best,
Dan.
Thanks Dan!
But better the LT, right?
I am considering getting it for Asian roads... When the road/path is bad I basically just ride standing over the bicycle, but if the road is all day bad... :D
Which kind of maintenance does it require? Any parts to change after X Km?
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Hi CT!
As to which is "better"...it depends on available clearance and intended use. For me, the greater travel of the LT was better for using the Nomad unladen on rough logging roads and cross-country. I have greatest need for it when riding the bike unladen. With a load, the ride smooths out very nicely...but the TBLT makes it nicer for me all 'round.
I'm fortunate my Nomad (and my fit on it) allows plenty of clearance for the LT. Be sure to check the measurements on the Thudbuster website before buying.
For your intended use, the greater travel of the LT sounds most ideal. I really don't have to stand for bumps very often at all now I use the TBLT. James' experience earlier in this thread mirrors mine.
TB have a pivot rebuild kit, spare elastomers, and replacement tension bolt. I suppose if I were going to be away for an extended period in remote areas, I'd take all those though it is unlikely I'd need them. Maintenance is generally down to occasionally oiling the pivots. I think the neoprene dust cover is the key to sealing out dust and moisture and will greatly aid service life/reduce maintenance. A spare tension bolt would keep the lot together and ridable in the very unlikely event the original broke.
Beyond the cover and occasional oiling, mine has yet to require any service or show wear. However, anytime you introduce something with moving parts, there is the potential for problems. A rigid post will be the least risk/hassle, but I found the TBLT well worth it for me in terms of unladen ride comfort and reduced fatigue. So far, it has been one of my most useful accessories. By the way, I ride with a 45° back angle. I found the stock elastomer ideal for my needs and didn't even need to adjust tension or preload, just use it as delivered. As with so many things, individual experience is bound to differ, but so far there has been no downside for me when used with my Brooks B.17. With my fast, light, smooth cadence I've noticed no bobbing. It can be a problem to fitting some clamp-on underseat bags, but the bags can usually be modified pretty easily. I'm currently using straps on my Ortlieb but intend to mill a new bracket from aluminum billet so I can mount the bag solidly to a wider part of the saddle rails and still clear the post linkage.
All the best,
Dan.
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Hi CT!
As to which is "better"...it depends on available clearance and intended use. For me, the greater travel of the LT was better for using the Nomad unladen on rough logging roads and cross-country. I have greatest need for it when riding the bike unladen. With a load, the ride smooths out very nicely...but the TBLT makes it nicer for me all 'round.
I'm fortunate my Nomad (and my fit on it) allows plenty of clearance for the LT. Be sure to check the measurements on the Thudbuster website before buying.
For your intended use, the greater travel of the LT sounds most ideal. I really don't have to stand for bumps very often at all now I use the TBLT. James' experience earlier in this thread mirrors mine.
TB have a pivot rebuild kit, spare elastomers, and replacement tension bolt. I suppose if I were going to be away for an extended period in remote areas, I'd take all those though it is unlikely I'd need them. Maintenance is generally down to occasionally oiling the pivots. I think the neoprene dust cover is the key to sealing out dust and moisture and will greatly aid service life/reduce maintenance. A spare tension bolt would keep the lot together and ridable in the very unlikely event the original broke.
Beyond the cover and occasional oiling, mine has yet to require any service or show wear. However, anytime you introduce something with moving parts, there is the potential for problems. A rigid post will be the least risk/hassle, but I found the TBLT well worth it for me in terms of unladen ride comfort and reduced fatigue. So far, it has been one of my most useful accessories. By the way, I ride with a 45° back angle. I found the stock elastomer ideal for my needs and didn't even need to adjust tension or preload, just use it as delivered. As with so many things, individual experience is bound to differ, but so far there has been no downside for me when used with my Brooks B.17. With my fast, light, smooth cadence I've noticed no bobbing. It can be a problem to fitting some clamp-on underseat bags, but the bags can usually be modified pretty easily. I'm currently using straps on my Ortlieb but intend to mill a new bracket from aluminum billet so I can mount the bag solidly to a wider part of the saddle rails and still clear the post linkage.
All the best,
Dan.
Thank you very much for the advice! ;-)
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Hi Dan, nearly two years since your last post on this subject, how is the TBLT performing?
Andy
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Hi Dan, nearly two years since your last post on this subject, how is the TBLT performing?
Despite pretty extensive use on rough logging roads, the Thudbuster LT (Long Travel) seatpost is almost indistinguishable from new in terms of function. There is now a barely discernible amount of lateral play compared to new, but this is only detectable when I manually (and gently) twist the saddle...it is not even enough to elicit a "click". I surely can't feel it while riding.
I do oil the pivots periodically with a Teflon-based lube and I do use the dust cover. I believe both those things are contributors to long life. I also take care not to reef (twist with force) on the saddle, which could place undue lateral torque on the bushings and pivot pins.
I did have an initial problem with a maddening click, wrote Cane Creek/Thudbuster about it, showed I had tried all their suggestions and detailed additional things I had tried -- a pretty exhaustive list. They figured it was a bad pivot/bushing and sent me a replacement under warranty with the tool to install it. A 30-second job to replace, the new bushing (it only required one) did the trick and the 'post has been quiet ever since.
Very pleased, very happy.
I have Thudbuster ST (Short Travel) seatposts on two of my randonneur bikes and have also been happy with them. It is horses for courses, really. The LT requires a good bit of room between the seatpost binder bolt and the saddle rails, so it would not fit the rando bikes with their horizontal top tubes. The ST posts fit fine, and do their job in that capacity -- smoothing out things like expansion joints and chip-seal over long 300-400km days in the saddle; I return home less fatigued. The ST posts use a single rubber puck. I found despite Cane Creek's/Thudbuster's warnings and recommendations, my positioning on the bike did not place enough weight on the saddle to activate the Medium puck indicated by my weight. I switched to a Soft puck and all works as intended with no bottoming-out.
The LT on the Nomad has much more travel and is much more tunable due to the ability to mix-match elastomers in the stack. The recommended Medium elastomer stack proved fine for me on the Nomad. The longer travel is most appropriate for my use on rough roads, goat tracks, logging roads, and poor gravel roads. I still post (stand) on the biggest bumps, as the rebound from the seatpost could be problematic in those situations. This is a nice feature of suspension seatposts -- you can lock them out at any time by simply standing on the pedals.
The LT differs from the ST by stacking the elastomers on a long bolt, held by a nylock nut and some washers. I have decided it is a potential long-term wear item and there have been isolated reports of this bolt breaking, primarily because a) the users did not occasionally grease the elastomer stack where the bolt passes through, causing wear on the bolt shaft and b) Some bolts were apparently a bit brittle and failed under rebound. I figured it would be a Wise Thing to order and carry a spare for my tours in the back-of-beyond. The bolt, nut, and washer weigh very little and are small so it is no bother. This caution does not affect the ST model which uses the rubber puck instead of stacked elastomers.
One additional word of possible caution: I am a spinner, someone who pedals with a fast, light ("hummingbird") low-torque cadence in round circles. As a result, I have no problem with these seatposts "bobbing" while under drive. However, I think that could potentially be a problem for "mashers" -- people who pedal with a high-torque, low-speed cadence and a pronounced power stroke on every revolution of the crank.
All the best,
Dan.
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Thanks Dan, as usual your 10c has a $1.95 value ;D.
Andy
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Hi Dan !
I think about to add a suspension seatpost, the most confortable, reliable seems to be the Cane Creek Thudbuster LT but i have a doubt if it will be fine for me...
Because, my Nomad have a long top tube (565L), even if currently i feel confortable, i think with the Thudbuster LT each time damping movement, i move a little further from the handlebars..
Is it right Dan ? Do you think it will be a real problem ?
Maybe is there a counterpart ? from the family of telescopic suspension seat post ? ..
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Hi Julien!
Your question is a good one and one I had asked myself as well. I use my size 590M Nomad with drop handebars. Despite the longer "Medium" (M) top tube, I find I can achieve the same position as my other drop-bar bikes by fitting compact drop 'bars with less forward reach and also a shorter reach (60mm) stem. I've found no detriment in handling or steering in my use. However, like you I was initially concerned about anything that could increase my reach to the handlebars because it was just right with my setup and I didn't want longer. So far, all has been well. I will explain why below:
The Thudbuster LT (ST also) is a parallelogram design, so the distance between saddle-top and bottom bracket remains pretty constant as the clamp declines down-and-rearward under bumps.
While this keeps saddle height effectively constant (but does change effective distance behind the bottom bracket in a dynamic fashion as you hit bumps), it does allow for a change in effective top tube length. I use the word "effective" because it is a dynamic process. The top tube doesn't actually change length but it feels a little like it because the saddle moves rearward a little as it moved down. That's a key point: It moves "a little" and only while responding to a bump, the distance it moves depends on the size of the bump.
The thing is, the Thudbuster 'posts in my actual use do not have the full travel promised -- they bottom out against the rising-rate of the compressed elastomer stack or rubber puck (depending on LT or ST model) before full travel can be reached. The designer and Cane Creek confirmed this with me in correspondence. This means the difference in reach to the handlebars throughout its travel at at the extremes is also less than you would think.
On various bikes in my fleet, I have two LTs and two STs. Despite my best efforts using things like tearable tape at the limits and so on, I have not been able to accurately measure the actual travel on my 'posts, so I cannot give you any accurate figures. In one test, I mounted a thin wooden dowel on my rear rack to measure where the travel extremes should have been, rode the bike on a rough road and found the markers undisturbed, so I know travel was something less than that. Mounting a camera to the rear rack and taking video it appears the travel on all the seatposts is less than the full stated range, but I'm not sure how much less because it is so hard to measure in practice.
This I do know: the ST (Short Travel) Thudbusters are ideal for my randonneur-road touring bikes in terms of taking the edge off rough chip-sealed pavement and concrete expansion joints and do a lot for making me feel more comfortable on long road rides. The longer the ride, the less fatigued I feel at the end and this really shows up on rides of 300-400km/day. However, the short-travel posts really do nothing for me on things like sharp frost-heaves, deep potholes and roots that have sharply bulged a paved surface. I have to use the same care in those circumstances as I would with a rigid seatpost. Hit something like that hard and you'll know it!
In contrast, the LT (Long Travel) Thudbusters work much better at damping much larger bumps than those mentioned above because it has more travel. I use mine on rough gravel and ballasted logging roads, though potholes and over root- and frost-heaves and they really help in that regard, making a noticeable difference and greatly reducing the number of times when I would otherwise stand to ease the road shock transmitted from the rear wheel up through my neck.
A couple things to keep in mind regarding my use and generally:
1) All my bikes have drop handlebars and I prefer setting my bikes up so I have a 45° back angle. Because of this, I place less body weight on the THudbusters than I would if sitting more upright. Because the 'posts are supporting less weight, I have found I need to go with a softer elastomer stack or rubber buck than my weight alone would indicate. Otherwise, the recommended durometer is just too stiff to get much benefit. This is a huge factor in how much actual travel I get from these parallelogram suspension seatposts. If your bike is setup so you're sitting much more upright, then you'll also get more travel, both downward and rearward.
2) Thudbusters don't mean you can or should remain seated over all bumps! I still post (stand up on the pedals) when I expect a big hit and this avoids any recoil effect where it might feel as if the 'post is launching me. It doesn't take long to learn what size bumps can be ridden seated and which require a quick standup.
3) I would much prefer to fit the LT model to all my bikes as it is more tunable (elastomer stack vs single molded rubber puck) and has a greater range of shock absorption. However, the limiting factor is the space available. The longer travel requires longer link-arms and not all my bikes have the clearance to allow this. That's why the road bikes (with horizontal top tubes) get the ST models; they simply have no room to fit the LT version unless the saddle were raised too high to be comfortable for me.
3) The Thudbuster pivots are highly polished stainless steel tubes riding in bronze bushings. This is appropriate for fretting loads. It also means the pivots should be lubed periodically and kept clean to reduce wear. I ordered the fitted neoprene sleeves for all my Thudbusters when I got them, fitted them at installation, and have found the pivots stay really clean with much longer lubrication intervals than if the posts were open (compared to the experience of friends who left theirs open) -- a bit like fitting a Hebie Chainglider vs an open chain.
4) Fitting a saddle to a Thudbuster is not so straightforward as with a conventional rigid 'post, so if you are switching, I would recommend taking careful measurements of...
a) The usual difference in height from bottom bracket center to saddle rails along the seatpost centerline.
b) Distance between steerer center and saddle nose.
c) Distance between underside of saddle at nose and top tube.
...so you can duplicate your position on the Thudbuster. Installation is fussy because there are two bolts to clamp the saddle rails. The forward one is fitted with a ring to serve as a thumbscrew. You first get that as tight as you can with finger pressure, then torque the rear bolt to spec with an allen key bit. Trouble is, as that rear bolt is torqued, the saddle tips rearward, so your initial adjustments will likely need to be redone a couple of times to get the saddle where it was on your old rigid 'post.
5) When you first sit on the saddle, your body weight will compress the elastomer stack or rubber puck, causing it to settle ("sag") and decline down-and-rearward a little. This can be addressed in one, the other, or a mixture of two ways: Either set the seatpost height a little higher than with a rigid 'post or set the saddle nose forward a little more than with a rigid 'post.
I chose the latter, pushing my saddle forward 4-5mm to serve as a preload for my body weight. Thinking about it more closely, I think this is a partial answer to your question, Julien: If your bike were setup like mine and with similar weight-elastomer settings, you could expect an increase in static reach at rest of about 4-5mm - easily compensated for by moving the saddle forward by that amount to put it back the same. Any increase in reach due to travel could be figured as a rising rate calculation (based on the compression curve of the damping medium, whether elastomer stack or rubber puck). I just went out to the garage where my Nomad is parked and draped my chest over the saddle, loading it with more and more of my body weight. I would =guess= I managed to achieve about 1cm of rearward travel and 1cm of downward travel total under as much load as I could apply to simulate a really big bump. That would total 2cm of travel, but only 1cm rearward and then only momentarily at close to full effective travel.
Is it right Dan ? Do you think it will be a real problem ?
I really don't think it will be a big problem in actual use, but it will depend on variables like your body weight, how upright you choose to sit, how close you are to not reaching the handlebars, how big a bumps you expect to hit while seated and the specific elastomer durometer you fit in the stack.
Maybe is there a counterpart ? from the family of telescopic suspension seat post ? ..
I haven't gotten along with telescopic seatposts to date, finding they tend to stick to some extent at points throughout their travel and work less freely and my knees don't tolerate the difference in effective saddle height so well as with a parallelogram design. That said, there are other parallelogram seatposts on the market and they work very nicely as options to choosing a Thudbuster. I went the Thudbuster route because it is widely distributed and replacement parts are available for when/if they wear out, unlike some others and there is good warranty coverage. I had to make use of this on one LT model when I made a warranty claim for a clicking pivot. After I described the steps I'd taken to isolate and try to address the problem, Cane Creek promptly sent me a replacement pivot and the tool to fit it, all free of charge. Terrific service. My other three posts have so far been problem-free.
Hopefully, something in the above will prove helpful to you.
All the best,
Dan.
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A little addendum to the above...
If you get the elastomers setup properly, you really won't feel the Thudbuster "working" as you normally ride along. It just feels like the bumps aren't as sharp. Yes, you can deliberately induce some suspension action if you try (it is kind of fun to sometimes do so and feels like a little kid's spring-framed hobby horse), but normally it just feels (to me) like you had fitted tires with much larger cross-section filled with less air...but without changing the ride of the bike.
Keep in mind I'm a spinner who pedals at a fast, light, round high-rev "hummingbird" cadence and so I don't feel any bobbing when I pedal. Things might be different if you "mash" the pedals with a hard, cyclic up-down stroke.
Best,
Dan.
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Super detailed answer.. lovely Dan 😑
There is this one, it seems a good compromise with 5cm of clearance, available for long travel model : http://byschulz.com/komponenten/sitzkomfort/parallel-gefederte-sattelstuetze-g2/
Or this one but only 3,5 cm of clearance : https://www.kickstarter.com/projects/redshiftsports/shockstop-seatpost-add-suspension-to-your-bike
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There is this one, it seems a good compromise with 5cm of clearance, available for long travel model : http://byschulz.com/komponenten/sitzkomfort/parallel-gefederte-sattelstuetze-g2/
Julien,
I have not used the Schulz 'post, but a friend of mine in Germany purchased this seatpost and reports he has been very happy with it. No problems at all after a year of use.
I have not seen or used the Redshift seatpost, so I have no experience with it I can pass on to you.
One potential issue for non-Thudbuster parallelogram seatposts is whether the saddle rails will clear the linkages at the front through the whole range of available travel. I know some fitments of Brooks saddles on the SunTour seatpost result in an initial interference and "clicking" sound until the edge of the aluminum seatpost link wears(!) away. It seems this might initially limit travel as well. Our own Forum member StuntPilot has noticed this and so far as I know, remains very happy with his SunTour parallelogram suspension seatpost even after extensive use.
I do like the idea of adjustable springs, but I don't have personal experience with them.
I made (they are relatively easy to construct if you have machining tools) a telescopic suspension seatpost that has been in operation for my tandem stoker the last 15 years or so. She reports it is helpful and won't ride without it, but I do notice it has noticeably more "stiction" (sticky friction) than my parallelogram Thudbusters, so it hangs up a little at various points in its movement.
Have you made a choice yet? If so, I'd love to hear how you like your new suspension seatpost, Julien.
All the best,
Dan.
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Hi Dan,
My preference is for the BySchulz G.2 LT .. (27.2 diameter x 380 length in mm)
I don't have my Nomad next to me, because i'm not at home at this time, but i think dimensions 27.2X380 mm will fit properly...
I'll tell you the feedback :)
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I'll tell you the feedback
Perfect, Julien; thanks! :)
All the best,
Dan.
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I received my Byschulz suspension seat post (used but as new), and because it was a correct price, i didn't choose the right recommendation about hardness.
The spring installed is recommended for people between 80 to 105 kg, and me i weigh 70 kg.
By Schulz recommendation for me, is a spring more flexible for people between 60 to 85 kg
I can't try my suspension seat post currently (i'm not at home), but do you think i make a mistake ?
However, i can always buy a new spring for 20 euros.
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I can't try my suspension seat post currently (i'm not at home), but do you think i make a mistake ?
Hmm. If it were me, here is what I would do:
1) Wait till I could get home and then install the seatpost and try it. Where it is used, it is unlikely you can return it, so well worth a try.
2) If the spring proves to be too hard (I think it will), then I would order the replacement spring.
3) If you are pressed for time (i.e. need it for a tour that will happen soon), then I would order the more appropriate spring right away so you can try it soonest.
I have found actual spring tensions in suspension seatposts vary according to your riding position (a factor beyond "recommended rider weight"). Because I use drop handlebars and prefer a 45° back angle, I require a softer spring than a more upright riding position would indicate. I simply don't put enough weight on my saddle to effectively activate the seatpost (in my case, Thudbuster LT and ST models) if I use the recommended "springs" (elastomers).
Hope this helps.
Best,
Dan.
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Hi Dan, thanks
I imagined because the nomad is confortable loaded without suspension seatpost, than i don't need to have a softer spring, and a little harder spring could be enough..
I will make a feedback later
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I imagined because the nomad is confortable loaded without suspension seatpost, than i don't need to have a softer spring, and a little harder spring could be enough..
It might be okay! If so, you can save the 20 Euros. :)
I find I don't need my suspension seatpost(s) when riding fully loaded, but it sure helps -- is even necessary -- for me when riding the Nomad unladen on really rough roads. I will make a feedback later
Thanks! This will help others in the future and I'm really interested in your experience with this seatpost. My friend has one of this brand and likes it very much; I hope you will also like it.
Best,
Dan.
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First conclusive test :)
It's impressive how comfortable it is. The back is much less solicited.
Finally, even if i ordered the softer spring to compare, i choose to ride with the harder, i think it does very well the job, without much bouncing effect.
However, the softer spring will be fine for path only and bike not loaded
(https://i93.servimg.com/u/f93/19/07/93/69/th/img_2013.jpg) (https://servimg.com/view/19079369/247)
PS: Do not forget to add a drop of Loctite on torx screws.
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Thanks for the update, Julien; all sounds good!
Best,
Dan.